(a) Field of the Invention
The present invention relates to a display unit having a screen adjustment function and, more particularly, to a display unit having a screen adjustment function for enlarging/reducing the effective size and moving the effective area of the screen of the display unit.
Display units having an on-screen-display (OSD) function are used in recent days, wherein desired characters and/or patterns are additionally displayed on a desired location of the screen of the display unit while superimposed with a main image. In a conventional display unit with or without an OSD function, when the display unit is subjected to an initial screen adjustment, an increase or decrease in numerical values or an expansion or contraction in bar charts are generally used for showing the amount of operation upon depression of a dedicated push button for enlargement/reduction or movement of the effective screen area in the vertical or horizontal directions.
In the initial screen adjustment, the intensity (brightness) control for the display unit is effected substantially without any dissatisfaction of the operator due to the feasibility of observation of amount of the operation on the screen simply by observing the screen. On the other hand, the movement or enlargement/reduction of the effective screen area in the initial screen adjustment generates dissatisfaction by the operator because the amount of operation represented by the numerical value does not effectively provide perception of the amount of operation for the enlargement etc.